CVE-2026-121737
Proxygen Use-After-Free Vulnerability
Description
When a remote, unauthenticated HTTP/1.1 client pipelined the start of a second request and then stopped reading, proxygen's coroutine-based HTTP session could free that pipelined stream while resetting the connection's streams on the resulting write timeout, then go on to use it. This can crash the server, leading to denial of service, and may allow memory corruption with further impact. This issue affects proxygen versions prior to v2026.11.09.00.
INFO
Published Date :
Nov. 11, 2026, 5:17 p.m.
Last Modified :
Nov. 11, 2026, 5:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
Solution
- Update Proxygen to version v2026.11.09.00 or later.
- Apply available security patches for Proxygen.
- Monitor server stability after the update.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-121737.
| URL | Resource |
|---|---|
| https://github.com/meta/proxygen/commit/daf245bba7fe1304b9491403fe56f91153299781 | |
| https://www.facebook.com/security/advisories/cve-2026-121737 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-121737 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-121737
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-121737 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-121737 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Nov. 11, 2026
Action Type Old Value New Value Added Description When a remote, unauthenticated HTTP/1.1 client pipelined the start of a second request and then stopped reading, proxygen's coroutine-based HTTP session could free that pipelined stream while resetting the connection's streams on the resulting write timeout, then go on to use it. This can crash the server, leading to denial of service, and may allow memory corruption with further impact. This issue affects proxygen versions prior to v2026.11.09.00. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/121xxx/CVE-2026-121737.json">CVE-2026-121737</a> Added Reference https://github.com/meta/proxygen/commit/daf245bba7fe1304b9491403fe56f91153299781 Added Reference https://www.facebook.com/security/advisories/cve-2026-121737